PROJECT SUMMARY/ABSTRACT War veterans have a significantly increased risk of fatal and nonfatal traumatic injury in the years immediately following combat deployments. Intentional self-harm injuries (e.g., suicide) are well- documented sources of veterans' fatal injuries. Firearms are the most commonly used mechanism in veterans' suicide deaths, and are involved in up to 60% more veteran suicides than non-veteran suicides. Little is known about veterans' nonfatal firearm injuries or their unintentional firearm injuries, even though these comprise the majority (81%) of all firearm-related injury events. Veterans have a higher prevalence of firearm ownership and more training with firearms than most United States (US) citizens. They also value firearms for recreational purposes, protecting themselves and their families, and upholding 2nd Amendment rights. Research to better understand firearms as a mechanism of injury among combat veterans could help prevent fatal and nonfatal traumatic injuries, but is profoundly lacking. There are over 2.7 million veterans of the recent wars in Iraq and Afghanistan. To better understand the full spectrum of firearm injuries (fatal and nonfatal; violent and unintentional) in this population of combat veterans, we are collaborating between federal (e.g., Department of Veterans Affairs) and state (Oregon) agencies to link data that will allow us to analyze the rates, risk factors, and circumstances of injury. The first aim of this project is to develop a model system for linking, sharing, and negotiating joint ownership of these key databases across agencies. Single databases exist that contain healthcare, or injury, or mortality data for veterans, but these data are maintained by separate organizations within separate agencies. We are working across organizations and agencies to develop a system that will result in an integrated database containing pre-event, event, and post-event (outcomes) data on firearm injuries. The second aim of this project is to use this linked database to estimate rates, identify risk factors for, and examine consequences of all firearm injuries among Iraq and Afghanistan War veterans. Analyses will compare: 1) veterans to non-veterans; and 2) veterans involved in firearm injuries to veterans not involved in firearm injuries. Notably, we will use healthcare records from the VA, Medicare and Medicaid, and other state data to identify health factors (e.g., diagnoses; prescriptions) that are associated with veterans' firearm injuries, as well as outcomes of these injuries. Overall, we hypothesize that certain demographic, military, and health factors are associated with veterans' risk of firearm injury. This R21 will establish feasibility and pilot data for an expanded, multistate database linkage in which we will examine risk factors for veterans' fatal and nonfatal firearm injuries in greater detail and across a larger US region. Ultimately, this line of work will lead to medical or public health interventions to help reduce fatal and nonfatal traumatic injuries among veterans in the years after their combat deployments.